There are many approaches to obtaining high-resolution images and three dimensional volumetric data sets, but all have limitations. Many techniques involve reconstructing volumes of information from sections, either physical sections or optical sections. Recently, James Sharpe, Ulf Ahlgren, Paul Perry, Bill Hill, Allyson Ross, Jacob Hecksher-Sørensen, Richard Baldock, and Duncan Davidson have developed an optical technique that is analogous to computed tomography (CT). Whereas clinical CT involves an X-ray source and detector rotating around the patient, optical projection tomography (OPT) has the specimen rotating within an optical pathway.

In the beginning there was water-the first stain that delineated structure within a polymeric system. The polymerwas natural rubber (NR) and the system was an air-dried film of natural latex. Grenquist reported in 1929 that a dried film of natural rubber latex soaked in hot water became milky (Figure 1) and, at that stage, the latex particles could be detected by the optical microscope (OM), The contrast mechanism was provided by the absorption of water by the naturally occurring proteinaceous layers present on the congealed NR particle surfaces. There was little demand for polymer staining until the age of electron microscopy.

The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The reliability of the CLSM to obtain specific measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. For many applications it is useful to know the CLSM system's performance prior to acquiring data images so the necessary resolution, sensitivity and precision can be obtained. Applications involving deconvolution, FRET and quantification necessitate that the confocal microscope is correctly configured and operating at the highest performance levels.

The most persistent misconception made in digital imaging among those who use our core facility involves the understanding of digital resolution; and the greatest mistakes result from a mis-use of the “Image Size” dialogue box in Adobe Photoshop. Add to that, an intractable desire to use Microsoft PowerPoint and to somehow make Photoshop and PowerPoint agree about the nature of images that open in both programs, weighted toward the miserable resolutions and compression required by PowerPoint, changes in original data become as common as dandelions on a lawn. Yet, changes in data that result from increasing or, more commonly, decreasing pixels (what is called re-sampling), can be avoided.

Resolution, as many of us have learned, is the ability to discriminate between two points in space, a phenomenon made easier by high contrast objects versus those that are low in contrast.

Thin films in microcircuits can vary from as little a few hundred angstroms, in the case of dielectrics such as silicon nitride and silicon dioxide, to several microns in the case of interconnects. However, most metallization systems used as interconnects and in active structures are generally in the order of 0.5 μm to 4 μm. Gold has a number of desirable properties such as high electrical conductivity, the ability to be easily electroplated, low residual stress after deposition, corrosion resistance etc., Gold is commonly found in microelectronic devices, particularly in high frequency applications like cellular telephony, fiber-optic amplifiers and other high frequency analog applications. An aqueous potassium iodide solution offers a fast and relatively safe method for the removal of thin gold films.

Recently, there was a suggestion on the MSA listserver about the use of osmium tetroxide (OsO4 and how to handle it. One suggestion was that ampoules be scored, placed in a glass jar, and the ampoule smashed to release the contents. This seemed like a very unsafe way to use osmium tetroxide or ruthenium tetroxide. The purpose of this article is to suggest a way to generate smaller amounts of these compounds in a safer manner than smashing ampoules and wondering about what to do with the unused portion after staining or storing. Another purpose is to discuss a new reaction indicator for mainly osmium tetroxide. The use of a reaction specific indicator was mandatory for judging the level or degree to which staining had proceeded in thin sections for the transmission electron microscope (TEM).

Glassy network epoxies have widespread applications as matrices for advanced composites As an alternative to thermal curing, electron beam (ebeam) processing has been demonstrated as a very powerful tool for achieving fast and efficient curing [1,2]. E-beam curing of epoxy based resins using suitable onium salts as initiators proceeds via a cationic mechanism. The final polymer network properties are highly dependent on processing conditions and curing kinetics. It was demonstrated that under certain processing conditions, heterogeneities can appear in the material, due to the agglomeration of initiator residue. Initially the initiator is miscible with the resin; however, reaction-induced phase separation occurs as the increasing molecular weight of the polymer reduces the solubility of the initiator.

SEM Instrument calibration is something most people don't always realize they need to do. Images look about right so the magnification seems close enough. Today, measurements are being done in specialized scanned beam metrology instruments everyday, so correct magnification calibration is very important. Calibration is probably more acknowledged from the point of the transmission electron microscope than for the scanning microscope. But, it still needs to be done. Today, people can buy SEM's that cost around $100,000 (refurbished ones somewhat less) to $2.5M with one instrument model from one manufacturer costing about $8M. Believe it or not, often the instrument buyer thinks that as soon as they get the instrument into their facility (since it is new and they paid a lot of money for it) that it is perfect and everything is correct.

All laboratory workers face the ongoing requirement that all chemicals and solutions used in the lab be labeled with the date of receipt or preparation, together with the expiration date of the chemical and the initials of the preparer, as well as any known hazards associated with that chemical. Officials from accrediting agencies, sometimes unannounced, pick and poke around laboratories looking for outdated chemicals and solutions, including biological stains left unsuspectingly at the back of a fridge or on a seldom used shelf.